One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,7)(4,6)(5,8)(9,10)(11,14)(12,15)(13,16)(17,20)(18,21)(19,22)(23,24)(25,26)(27,33)(28,36)(29,31)(30,35)(32,37)(34,38)(39,40) involution — undirected(1,2)(3,5)(4,6)(7,8)(10,11)(15,17)(16,18)(22,23)(25,27)(26,30)(28,34)(29,35)(31,33)(32,38)(36,39)(37,40) involution — undirected(1,2,4,6)(3,5,8,7)(13,21)(16,18)(19,24)(22,23)(26,31)(30,33)(32,36)(38,39)(9,11,14,10)(12,17,20,15)(13,18,21,16)(19,23,24,22)(25,28,29,37)(26,32,31,36)(27,34,35,40)(30,38,33,39)(1,3)(2,5)(4,8)(6,7)(9,12,14,20)(10,15,11,17)(13,19,21,24)(16,22,18,23)(25,27)(26,30)(28,34)(29,35)(31,33)(32,38)(36,39)(37,40)(1,2)(3,5)(4,6)(7,8)(9,13,14,21)(10,16,11,18)(12,19,20,24)(15,22,17,23)(25,26)(27,30)(28,32)(29,31)(33,35)(34,38)(36,37)(39,40)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.